Well, two things are obvious:
1. your procedure made successful connection to SQL*Plus
2. it was unable to open file specified in the path you provided.
Did you check existence of the file (sapdba_role.sql) at the specified directory?
If it exists, can you open it with a text editor (because it is an ordinary text file)? What do you see in it?
If it doesn't exist there, can you find it somewhere else, in another directory?
No? Then you, my friend, are in deep trouble. But, follow this link; there you'll find the script you're looking for. I really wouldn't know will it work on your system. As you probably already know, after things have gone from bad to worse, the cycle will repeat itself Good luck!